Grease Interceptor Maintenance Guidance
Why do you need a grease
interceptor?
A grease interceptor removes fats, oils,
and grease that coat city sewer lines
and cause sanitary sewer system
overflows. If an overflow occurs, you
may be responsible for clean-up costs
and property damage.
How does a grease interceptor
work?
Wastewater enters the unit after leaving
the kitchen. Most of the floating grease
remains at the top while the solids settle
at the bottom of the first chamber of the
unit (see diagram). Water flows into the
second chamber where more solids and
grease separate out. The remaining
water enters the sample box and then
flows out of the unit to the community
sewer.
Maintenance of your grease interceptor is required as a condition of your permit and to assure that the unit works properly.
How often do I need to clean my grease
interceptor?
Your permit requires that you clean your interceptor at a
regular frequency. An interceptor should be cleaned
once grease and solids have reached 25% of the total
liquid depth. Your cleaning frequency will depend upon
the capacity of your interceptor and the level of kitchen
activity at your establishment. If the amount of grease
being discharged causes or contributes to a blockage or
overflow, your interceptor must be cleaned more
frequently. Be sure that your grease hauler is doing a
complete pump-out of the unit and checking for repairs
during every service*. Also, make sure your hauler
provides you with a receipt to document that your
interceptor has been pumped.
* It is important to scrape and clean the walls and baffles
during pump-out to maximize the removal of FOG from
the interceptor. The materials removed should be
thoroughly vacuumed to prevent biological breakdown
and the unwanted release of gas.
What will an inspector look for
during an inspection of my grease
interceptor?
An inspector will look to see that you are
maintaining and pumping your grease
interceptor frequently enough to comply
with your permit and preventing grease
from discharging to the city sewer. They
will ask to see your grease interceptor
logs and pumping records, including the
dates that the grease interceptor was
pumped and by which licensed hauler.
Have these records available for the
inspector to review.
What are some Best Management
Practices (BMPs) for grease
interceptors?
Grease and solid food waste can build up
inside the interceptor and may cause the
interceptor to operate less efficiently.
Scraping grease and food waste into the
garbage before washing dishes will
minimize the amount of grease and solids
going into the grease interceptor and will
improve interceptor performance.
Installing drain screens at each sink will
also help prevent food waste from
entering the interceptor.
City of Cypress
Public Works Department
(714) 229-6740
Project-Pollution-Prevention